Shirataki noodles are long, white noodles. They are often called miracle noodles or konjac noodles.

They're made from glucomannan, a type of fiber that comes from the root of the konjac plant.

Konjac grows in Japan, China and Southeast Asia. It contains very few digestible carbs — but most of its carbs come from glucomannan fiber.

"Shirataki" is Japanese for "white waterfall," which describes the noodles' translucent appearance. They’re made by mixing glucomannan flour with regular water and a little lime water, which helps the noodles hold their shape.

The mixture is boiled and then shaped into noodles or rice-like pieces.

Shirataki noodles contain a lot of water. In fact, they are about 97% water and 3% glucomannan fiber. They're also very low in calories and contain no digestible carbs.

A variety called tofu shirataki noodles is very similar to traditional shirataki noodles, but with added tofu that provides a few additional calories and a small number of digestible carbs.

Summary Shirataki noodles are a low-calorie food made from glucomannan, a type of fiber found in the Asian konjac plant.

In one study, people with type 2 diabetes who took glucomannan for three weeks had a significant reduction in fructosamine, which is a marker of blood sugar levels (17).

In another study, people with type 2 diabetes who took a single dose of glucomannan before consuming glucose had significantly lower blood sugar levels two hours later, compared to their blood sugar after a placebo (18).

Summary Shirataki noodles can delay stomach emptying, which may help prevent blood sugar spikes after meals.

For some, the glucomannan in shirataki noodles may cause mild digestive issues, such as loose stools, bloating and flatulence (1).

However, it should be noted that glucomannan has been found to be safe at all dosages tested in studies.

Nevertheless — as is the case with all fiber — it's best to introduce glucomannan into your diet gradually.

In addition, glucomannan may reduce the absorption of certain medications, including some diabetes drugs. To prevent this, take your medication at least one hour before or four hours after eating shirataki noodles.

Summary Shirataki noodles are safe to consume but may cause digestive issues for some. They may also reduce the absorption of certain medications.